package cn.swenty.backstage.framework.util;

import java.io.File;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

public class ClassUtil {
	
	public static Map<String, List<String>> classPathMap = new HashMap<>();
	
	public static Object newObject(String className){
		Object t = null;
		try {
			Class<?>  class1 = Class.forName(className);
			t = class1.newInstance();
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		} catch (InstantiationException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		}
		
		return t;
	}

	/**
	 * 获取某包下（包括该包的所有子包）所有类
	 * @param packageName 包名
	 * @return 类的完整名称
	 */
	public static List<String> getClassName(String packageName) {
		return getClassName(packageName, true);
	}

	/**
	 * 获取某包下所有类
	 * @param packageName 包名
	 * @param childPackage 是否遍历子包
	 * @return 类的完整名称
	 */
	public static List<String> getClassName(String packageName, boolean childPackage) {
		List<String> fileNames = null;
		ClassLoader loader = Thread.currentThread().getContextClassLoader();
		String packagePath = packageName.replace(".", "/");
		URL url = loader.getResource(packagePath);
		if (url != null) {
			String type = url.getProtocol();
			if (type.equals("file")) {
				fileNames = getClassNameByFile(url.getPath(), null, childPackage);
			} else if (type.equals("jar")) {
				fileNames = getClassNameByJar(url.getPath(), childPackage);
			}
		} else {
			fileNames = getClassNameByJars(((URLClassLoader) loader).getURLs(), packagePath, childPackage);
		}
		return fileNames;
	}
	
	
	public static List<String>scanClasses(String basePackageName,Class<?> c){
		List<String> strings = scanClasses(basePackageName);
		List<String> ss = new ArrayList<>();
		for(int i=0;i<strings.size();i++){
			String str = strings.get(i);
			try {
				Class<?> fc = Class.forName(str);
				if(c.isAssignableFrom(fc)){
					ss.add(str);
				}
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		return ss;
	}
	
	public static List<String> scanClasses(String basePackageName){
		
		if(classPathMap.get(basePackageName)!= null){
			return classPathMap.get(basePackageName);
		}
		
		URLClassLoader loader =  (URLClassLoader) Thread.currentThread().getContextClassLoader();
		URL url = loader.getResource("");
		List<String> myClassName = new ArrayList<String>();
		if(url != null){
			String type = url.getProtocol();
			if (type.equals("file")) {
				myClassName = getClassNameByFile(url.getPath(), null, true);
				myClassName.addAll(getClassNameByJars(loader.getURLs(), "", true));
			}else{
				myClassName = getClassNameByJar(url.getPath(), true);
			}
		}
		for(int i=0;i<myClassName.size();i++){
			String cl = myClassName.get(i);
			if(cl.replaceAll(basePackageName.replace("*", "([\\s\\S]*)"),"").length() == cl.length()){
				myClassName.remove(i);
				i--;
			}
		}
		classPathMap.put(basePackageName, myClassName);
		return myClassName;
		
	}

	/**
	 * 从项目文件获取某包下所有类
	 * @param filePath 文件路径
	 * @param className 类名集合
	 * @param childPackage 是否遍历子包
	 * @return 类的完整名称
	 */
	private static List<String> getClassNameByFile(String filePath, List<String> className, boolean childPackage) {
		List<String> myClassName = new ArrayList<String>();
		File file = new File(filePath.replace("%20", " "));
		File[] childFiles = file.listFiles();
		for (File childFile : childFiles) {
			if (childFile.isDirectory()) {
				if (childPackage) {
					myClassName.addAll(getClassNameByFile(childFile.getPath(), myClassName, childPackage));
				}
			} else {
				String childFilePath = childFile.getPath();
				if (childFilePath.endsWith(".class")) {
					childFilePath=childFilePath.replaceAll("/","\\\\");
					childFilePath = childFilePath.substring(childFilePath.indexOf("\\classes") + 9, childFilePath.lastIndexOf("."));
					childFilePath = childFilePath.replace("\\", ".");
					myClassName.add(childFilePath);
				}
			}
		}

		return myClassName;
	}

	/**
	 * 从jar获取某包下所有类
	 * @param jarPath jar文件路径
	 * @param childPackage 是否遍历子包
	 * @return 类的完整名称
	 */
	private static List<String> getClassNameByJar(String jarPath, boolean childPackage) {
		List<String> myClassName = new ArrayList<String>();
		String[] jarInfo = jarPath.split("!");
		String jarFilePath = jarInfo[0].substring(jarInfo[0].indexOf("/"));
		String packagePath = jarInfo[1].substring(1);
		try {
			if(jarFilePath.endsWith(".jar")){
				JarFile jarFile = new JarFile(jarFilePath);
				Enumeration<JarEntry> entrys = jarFile.entries();
				while (entrys.hasMoreElements()) {
					JarEntry jarEntry = entrys.nextElement();
					String entryName = jarEntry.getName();
					if (entryName.endsWith(".class")) {
						if (childPackage) {
							if (entryName.startsWith(packagePath)) {
								entryName = entryName.replace("/", ".").substring(0, entryName.lastIndexOf("."));
								myClassName.add(entryName);
							}
						} else {
							int index = entryName.lastIndexOf("/");
							String myPackagePath;
							if (index != -1) {
								myPackagePath = entryName.substring(0, index);
							} else {
								myPackagePath = entryName;
							}
							if (myPackagePath.equals(packagePath)) {
								entryName = entryName.replace("/", ".").substring(0, entryName.lastIndexOf("."));
								myClassName.add(entryName);
							}
						}
					}
				}
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		return myClassName;
	}

	/**
	 * 从所有jar中搜索该包，并获取该包下所有类
	 * @param urls URL集合
	 * @param packagePath 包路径
	 * @param childPackage 是否遍历子包
	 * @return 类的完整名称
	 */
	private static List<String> getClassNameByJars(URL[] urls, String packagePath, boolean childPackage) {
		List<String> myClassName = new ArrayList<String>();
		if (urls != null) {
			for (int i = 0; i < urls.length; i++) {
				URL url = urls[i];
				String urlPath = url.getPath();
				// 不必搜索classes文件夹
				if (urlPath.endsWith("classes/")) {
					continue;
				}
				String jarPath = urlPath + "!/" + packagePath;
				myClassName.addAll(getClassNameByJar(jarPath, childPackage));
			}
		}
		return myClassName;
	}
	
}